77685449 has 2 divisors, whose sum is σ = 77685450. Its totient is φ = 77685448.

The previous prime is 77685409. The next prime is 77685469. The reversal of 77685449 is 94458677.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 55056400 + 22629049 = 7420^2 + 4757^2 .

It is a cyclic number.

It is not a de Polignac number, because 77685449 - 2⁸ = 77685193 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 77685397 and 77685406.

It is not a weakly prime, because it can be changed into another prime (77685409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38842724 + 38842725.

It is an arithmetic number, because the mean of its divisors is an integer number (38842725).

Almost surely, 2^77685449 is an apocalyptic number.

It is an amenable number.

77685449 is a deficient number, since it is larger than the sum of its proper divisors (1).

77685449 is an equidigital number, since it uses as much as digits as its factorization.

77685449 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1693440, while the sum is 50.

The square root of 77685449 is about 8813.9349328209. The cubic root of 77685449 is about 426.6907486272.

The spelling of 77685449 in words is "seventy-seven million, six hundred eighty-five thousand, four hundred forty-nine".